Optical circuit switching has been incorporated into data centers employing electrical packet switches. The article “Helios: A Hybrid Electrical/Optical Switch Architecture for Modular Data Centers” by N. Farrington et al., SIGCOMM'10, Aug. 30-Sep. 3, 2010, ACM 978-1-4503-0201-2/10/08, copyright 2010, describes a hybrid electrical/optical data center switch architecture capable of effectively combining the benefits of both optical circuit switching and electrical packet switching, and delivering the same performance as a fully-provisioned packet-switched network for many workloads but at significantly less cost, less complexity (number of cables, footprint, labor), and less power consumption. The Helios hybrid electrical/optical switch architecture uses hardware flow counters to classify each flow as either a mouse flow or an elephant flow. The subset of traffic best suited to circuit switching is identified. Based on these classifications and flow measurements, the optical circuit elements of the hybrid electrical/optical system are reconfigured dynamically to prevent bottlenecks.